Boeing's flagship fleet of 787 Dreamliner aircraft will be grounded for the foreseeable future after a preliminary report from the National Transportation Safety Board (NTSB) said the cause of two battery fires had yet to be found, and that Japanese investigators are similarly baffled.
"We have not ruled anything out as a …

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Difficult fire suppression / fire extinguishing

It's a tricky proposition to extinguish a battery fire. Water may just accelerate the fire and inert gas would not necessarily stop the battery from burning (but might stop the fire from spreading). In chemistry labs, we'd have buckets of sand to suppress such difficult-to-extinguish fires, but that's a weighty proposition which won't save the battery. Maybe defective batteries should be ejected from the plane, backup batteries could ensure critical flight functions. But the FAA might not like such a solution.

Re: Difficult fire suppression / fire extinguishing

Re: Difficult fire suppression / fire extinguishing

"Maybe defective batteries should be ejected from the plane..."

This has an added benefit - the ensuing explosion would provide a way out should the plane be struggling to escape the gravity well of a singularity spawned by the collision of two spaceships from the future.

It'll get sorted...

It looks like I'm watching planes take a leap(?) forward with modern tech and I for one welcome our gigantic flying overlords - amazing. Considering all the experience, approvals and safety etc I'd guess the people involved are trying to minimize the chances of anybody dying because they fucked up! Also - If Yuasa can't sort battery problem nobody can!

This will make...

A great Air Crash Investigation/Mayday episode when they find out what's wrong with it.

I think because the press have been alerted and have gone in to panic mode regarding the frequency of these events (the Daily Mail will be proud of it) they have had to ground the planes. Nothing more.

" Initial tests at a facility in Arizona show no problems, while Japanese investigators report that their APU circuit boards are too badly burnt to provide meaningful data at this time."

Hopefully the entire facility will not burn to the ground --again-- when testing becomes spontaneously and spectacularly exothermic, as happened earlier in the 787 program. That would slow down the investigation.

Incorrect statement.

"The preliminary findings from the NTSB on the Boston fire report that the plane engineers noticed smoke and flames coming from the auxiliary power unit located under wings"

No. According to the NTSB preliminary report, a "mechanic noted flames coming from APU battery in aft electronics bay".

The aft electronics bay, which holds the battery in question (presumably used to start the APU), is indeed located more or less under the wings, slightly to the rear. The APU on the other hand is at the very end of the plane, as with most other planes (ATR72s being a notable exception, in that the right prop can be disengaged from the engine and the latter used as an APU). The APU is inside the tail cone. That hole that you'll see at the rear of your next plane, that's the APU exhaust.

I know a journo does not need to know this, but it's the second article where the same mistake has been made, and it is annoying and distracting.

I would have sent a correction using the link, but I don't like the mailto: URI. Why not just provide a form?

Re: Incorrect statement.

I would have sent a correction using the link, but I don't like the mailto: URI.

You know, I often wonder about people whose technology peccadilloes result in their foregoing functionality that would let them do something they want to do: "I could have just clicked on the link and sent an email. But I didn't because I think it's wrong. And now I've taken a bunch of my time to complain about it too. You're welcome. Good day, sir!

Re: From the country that brought us the Xbotch360 RROD

This definitely needs to be resolved

Lithium-ion batteries have always had fire issues. Find the problem and fix it. It's not like every 787 is having these fires. There has already been speculation that the charging circuit is the issue but this remains to be proven. Internal short-circuits on lithium-ion batteries is nothing new and the cause of past fires in laptops and other devices.

Re: This definitely needs to be resolved

If it's anything like the Comet problem...

... then the investigation will find nothing, the planes will be cleared to fly again, and then crashes will start occurring, probably over water.

After a heroic recovery of the remains of a Dreamliner from 7 miles down in the Pacific, they will recreate the accident and discover something completely new about battery technology. But by then Airbus will have taken over their markets....

Re: If it's anything like the Comet problem...

suppose what really makes me smile is that...

Here we are with a problem that is sufficiently arcane to have, so far, puzzled some of the world's top engineers in their fields, all of them with all available details of how the systems are set up and what's been found out to date. And here we have a whole bunch of commentards who know exactly what the problem is and how to fix it, based on the press reports. Makes you believe in crowd sourcing and wikipedia doesn't it...

Re: suppose what really makes me smile is that...

I've noticed similar situations with issues involving CPU design, high energy physics, automobile manufacturing, and any number of other fields known for rigorous training requirements and the need for highly experienced people.

It certainly is remarkable that the science and technology world hasn't seized on the clear advantages to be had by hiring from the pool of preternaturally talented Reg commenters; if I were offered a pool of people who would offer nearly instant and free solutions to the world's greatest manufacturing, technology, and science issues, in exchange only for their right to a feeling of smug superiority - why, I'd jump on the opportunity in an instant.

Remember the Sony Li-ion batteries with the internal short circuits?

Interesting info re electrical system

Having read the "battery that blew up a building" link....

..you see the battery is built by the Japanese, the chargers by the yanks and the whole thing is integrated by the French. So the Japanese bit will work and be built using SI measurements, the yank bit will be built of bailiing wire using US gallons or god-clods or something measurements and the French went for lunch then chucked the integration together before nipping off to integrate with their mistresses. All I know is that my feet swell up when I take a flight....I wonder if batteries do the same???

B787's technologies are Marketing's choices, not engineers ones

The technological choices Boeing took for the 787 were made by the Marketing Department, not by the technical engineers. Best proof is the use of composite materials, touted like marvels that would lead to a lighter aircraft. Marketing department just forgot that aluminium has not only a mechanical function but electrical functions too, making the plane a Faraday cage and providing electrical grounding. The result is engineers had to add a lot of metal to the carbon-based composites, making the 787 between 6 to 11 tons too heavy compared to expectations (cf for instance http://articles.economictimes.indiatimes.com/2012-08-09/news/33118779_1_b-787s-air-india-250-seater-aircraft). Nonetheless, Boeing' marketing dept. continues to claim 787 is lighter because of the use of composite materials.... BS.

Re: B787's technologies are Marketing's choices, not engineers ones

Whilst that might or might not be true you aren't supplying any evidence. Just because they've had to build in extra metal alongside the carbon structure it doesn't mean that the resulting structure is heavier than an all metal structure would have been. If you'd hoped to save 10 tons, and you have to put 5 tones of time in then you are still up 5 tons. I think you'll find it not unusual for initial weight estimates to be optimistic. They are, after all, for salesmen to use.

Re: B787's technologies are Marketing's choices, not engineers ones

Its not the first time composites have been used in civil aircraft. They have progressively used more and more composite parts for things like wings. They weave conductive threads into the composite to solve problems like lightning strikes. What is new is that this is the first time that they have been used for the fuselage.

The Boeing engineers came up with a bunch of targets to hit before they started on the project. Those targets will have been agreed with Marketing, who have to sell the damned thing, but the engineers wouldn't have agreed to anything that they didn't think they could do. As it happens they came in under their weight target, so they didn't have to use Lithium Ion cells,

A word of encouragement for the engineers...

I bet the loneliest job on the planet right now is that of Battery Power Systems Engineer at Boeing. I imagine the CEO of Boeing is not in a happy place right now, and CEOs under stress tend not to look kindly upon engineers who honestly say, "I do not know what the cause is, I am still researching."

Keep up the search, buddy. I'll raise my glass, one engineer to another.